PDF Text Box Design

I need a PDF document with text boxes designed to prevent layout shifting. The goal is to make data entry easy and efficient. The document should remain stable after adding text boxes. Another document we need redesigned has been made in word and then it is converted to a pdf. The problem with using word and our document it is such a large designed document that when we have 100 pages, the document is very slow and can cause a crash. We need this document redesigned more efficiently. This document also has unique identification numbers for each document. The document when converted to PDF currently gets a cert number based off the time and date. The watermark in the background is only for this sample, that is normally removed.